Col, I am separating from the AF in about a month. I applied to UChicago and Carnegie Mellon (won't hear back until early May) so I'll have a better idea of the value of the "veteran" status then. Being undecided about joining the military, one word of advice is to enlist for the shortest amount of time possible! The AF offers 4 and 6 year contracts, and the recruiter will try his best make you sign up for 6. It is not worth it! Also, you will probably want to take classes while you are in. People will encourage you to go to "AMU" or some other useless online college. Do whatever you can to go to the best local campus. Few of your peers will have similiar aspirations (Hopkins quality school) and more likely want to drink or play video games. If you can get into a top school right now I would recommend that over enlisting first. I couldn't, but I spent much of my free time with my nose in a textbook and I feel pretty optimistic about the future. I enlisted and, using kinder terms, it wasn't for me. I was lucky and able to separate before my contract is up, I enlisted a month after my 18th and turn 21 in July, but don't count on a similiar situation--the stars aligned for me.
In short, if you choose to enlist, start school ASAP. I'll be half way through my sophomore year by the time I begin full-time this fall. I should be able to graduate in under 3 years, so while I will be a bit older than my peers, I won't be a geezer. Also, choose a few schools you really want to attend and look at their transfer requirements. I really wanted to apply to the engineering schools at GTech and Michigan, but they have quite a few pre-reqs I couldn't meet.
Any specific questions feel free to ask.